/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.studyyoun.android.androidcommonbaselibrary.zxing.zxcamera;

import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Build;
import android.os.Handler;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.SurfaceHolder;

import com.studyyoun.android.androidcommonbaselibrary.zxing.zxapp.ZxPreferencesActivity;
import com.studyyoun.android.androidcommonbaselibrary.zxing.zxdecode.ZxPlanarYUVLuminanceSource;

import java.io.IOException;
import java.util.List;

/**
 * This object wraps the Camera service object and expects to be the only one
 * talking to it. The implementation encapsulates the steps needed to take
 * preview-sized images, which are used for both preview and decoding.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class ZxCameraManager {

    private static final String TAG = ZxCameraManager.class.getSimpleName();

    /**
     * 定义扫描框宽高
     */
    private static final int MIN_FRAME_WIDTH = 240;
    private static final int MIN_FRAME_HEIGHT = 240;
    private static final int MAX_FRAME_WIDTH = 480;
    private static final int MAX_FRAME_HEIGHT = 360;

    private static ZxCameraManager cameraManager;

    static final int SDK_INT; // Later we can use Build.VERSION.SDK_INT

    static {
        int sdkInt;
        try {
            sdkInt = Build.VERSION.SDK_INT;
        } catch (NumberFormatException nfe) {
            // Just to be safe
            sdkInt = 10000;
        }
        SDK_INT = sdkInt;
    }

    private final Context context;
    private final ZxCameraConfigurationManager configManager;
    private Camera camera;
    private Rect framingRect;
    private Rect framingRectInPreview;
    private boolean initialized;
    private boolean previewing;
    private final boolean useOneShotPreviewCallback;
    /**
     * Preview frames are delivered here, which we pass on to the registered
     * handler. Make sure to clear the handler so it will only receive one
     * message.
     */
    private final ZxPreviewCallback previewCallback;
    /**
     * Autofocus callbacks arrive here, and are dispatched to the Handler which
     * requested them.
     */
    private final ZxAutoFocusCallback autoFocusCallback;

    /**
     * Initializes this static object with the Context of the calling Activity.
     *
     * @param context
     *         The Activity which wants to use the camera.
     */
    public static void init (Context context) {
        if (cameraManager == null) {
            cameraManager = new ZxCameraManager(context);
        }
    }

    /**
     * Gets the ZxCameraManager singleton instance.
     *
     * @return A reference to the ZxCameraManager singleton.
     */
    public static ZxCameraManager get () {
        return cameraManager;
    }

    private ZxCameraManager (Context context) {
        this.context = context;
        this.configManager = new ZxCameraConfigurationManager();

        // Camera.setOneShotPreviewCallback() has a race condition in Cupcake,
        // so we use the older
        // Camera.setPreviewCallback() on 1.5 and earlier. For Donut and later,
        // we need to use
        // the more efficient one shot callback, as the older one can swamp the
        // system and cause it
        // to run out of memory. We can't use SDK_INT because it was introduced
        // in the Donut SDK.
        // useOneShotPreviewCallback = Integer.parseInt(Build.VERSION.SDK) >
        // Build.VERSION_CODES.CUPCAKE;
        useOneShotPreviewCallback = Build.VERSION.SDK_INT > 3; // 3 = Cupcake

        previewCallback = new ZxPreviewCallback(configManager,
                useOneShotPreviewCallback);
        autoFocusCallback = new ZxAutoFocusCallback();
    }

    /**
     * Opens the camera driver and initializes the hardware parameters.
     *
     * @param holder
     *         The surface object which the camera will draw preview frames
     *         into.
     * @throws IOException
     *         Indicates the camera driver failed to open.
     */
    public void openDriver (SurfaceHolder holder) throws IOException {
        if (camera == null) {
            camera = Camera.open();
            if (camera == null) {
                throw new IOException();
            }
            camera.setPreviewDisplay(holder);

            if (!initialized) {
                initialized = true;
                configManager.initFromCameraParameters(camera);
            }
            configManager.setDesiredCameraParameters(camera);

            SharedPreferences prefs = PreferenceManager
                    .getDefaultSharedPreferences(context);
            if (prefs.getBoolean(ZxPreferencesActivity.KEY_FRONT_LIGHT, false)) {
                ZxFlashlightManager.enableFlashlight();
            }
        }
    }

    /**
     * Closes the camera driver if still in use.
     */
    public void closeDriver () {
        if (camera != null) {
            ZxFlashlightManager.disableFlashlight();
            camera.release();
            camera = null;
        }
    }

    /**
     * Asks the camera hardware to begin drawing preview frames to the screen.
     */
    public void startPreview () {
        if (camera != null && !previewing) {
            camera.startPreview();
            previewing = true;
        }
    }

    /**
     * Tells the camera to stop drawing preview frames.
     */
    public void stopPreview () {
        if (camera != null && previewing) {
            if (!useOneShotPreviewCallback) {
                camera.setPreviewCallback(null);
            }
            camera.stopPreview();
            previewCallback.setHandler(null, 0);
            autoFocusCallback.setHandler(null, 0);
            previewing = false;
        }
    }

    /**
     * A single preview frame will be returned to the handler supplied. The data
     * will arrive as byte[] in the message.obj field, with width and height
     * encoded as message.arg1 and message.arg2, respectively.
     *
     * @param handler
     *         The handler to send the message to.
     * @param message
     *         The what field of the message to be sent.
     */
    public void requestPreviewFrame (Handler handler, int message) {
        if (camera != null && previewing) {
            previewCallback.setHandler(handler, message);
            if (useOneShotPreviewCallback) {
                camera.setOneShotPreviewCallback(previewCallback);
            } else {
                camera.setPreviewCallback(previewCallback);
            }
        }
    }

    /**
     * Asks the camera hardware to perform an autofocus.
     *
     * @param handler
     *         The Handler to notify when the autofocus completes.
     * @param message
     *         The message to deliver.
     */
    public void requestAutoFocus (Handler handler, int message) {
        if (camera != null && previewing) {
            autoFocusCallback.setHandler(handler, message);
            // Log.d(TAG, "Requesting auto-focus callback");
            camera.autoFocus(autoFocusCallback);
        }
    }

    /**
     * Calculates the framing rect which the UI should draw to show the user
     * where to place the barcode. This target helps with alignment as well as
     * forces the user to hold the device far enough away to ensure the image
     * will be in focus.
     *
     * @return The rectangle to draw on screen in window coordinates.
     */
    public Rect getFramingRect () {
        Point screenResolution = configManager.getScreenResolution();
        if (framingRect == null) {
            if (camera == null) {
                return null;
            }
            int width = screenResolution.x * 3 / 4;
            if (width < MIN_FRAME_WIDTH) {
                width = MIN_FRAME_WIDTH;
            } else if (width > MAX_FRAME_WIDTH) {
                width = MAX_FRAME_WIDTH;
            }
            int height = screenResolution.y * 3 / 4;
            if (height < MIN_FRAME_HEIGHT) {
                height = MIN_FRAME_HEIGHT;
            } else if (height > MAX_FRAME_HEIGHT) {
                height = MAX_FRAME_HEIGHT;
            }
            int leftOffset = (screenResolution.x - width) / 2;
            int topOffset = (screenResolution.y - height) / 2;
            framingRect = new Rect(leftOffset, topOffset, leftOffset + width,
                    topOffset + height);
            Log.d(TAG, "Calculated framing rect: " + framingRect);
        }
        return framingRect;
    }

    /**
     * Like {@link #getFramingRect} but coordinates are in terms of the preview
     * frame, not UI / screen.
     */
    public Rect getFramingRectInPreview () {
        if (framingRectInPreview == null) {
            Rect rect = new Rect(getFramingRect());
            Point cameraResolution = configManager.getCameraResolution();
            Point screenResolution = configManager.getScreenResolution();
            /*********************** �޸�Ϊ������ʼ ******************************/
            // rect.left = rect.left * cameraResolution.x / screenResolution.x;
            // rect.right = rect.right * cameraResolution.x /
            // screenResolution.x;
            // rect.top = rect.top * cameraResolution.y / screenResolution.y;
            // rect.bottom = rect.bottom * cameraResolution.y /
            // screenResolution.y;
            /*********************** �޸�Ϊ�������� ******************************/
            /*********************** �޸�Ϊ������ʼ ******************************/
            // rect.left = rect.left * cameraResolution.y / screenResolution.x;
            // rect.right = rect.right * cameraResolution.y /
            // screenResolution.x;
            // rect.top = rect.top * cameraResolution.x / screenResolution.y;
            // rect.bottom = rect.bottom * cameraResolution.x /
            // screenResolution.y;
            /*********************** �޸�Ϊ�������� ******************************/
            rect.left = rect.left * cameraResolution.y / screenResolution.x;
            rect.right = rect.right * cameraResolution.y / screenResolution.x;
            rect.top = rect.top * cameraResolution.x / screenResolution.y;
            rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;

            framingRectInPreview = rect;
        }
        return framingRectInPreview;
    }

    /**
     * Converts the result points from still resolution coordinates to screen
     * coordinates.
     *
     * @param points
     *            The points returned by the Reader subclass through
     *            Result.getResultPoints().
     * @return An array of Points scaled to the size of the framing rect and
     *         offset appropriately so they can be drawn in screen coordinates.
     */

    /**
     * A factory method to build the appropriate LuminanceSource object based on
     * the format of the preview buffers, as described by Camera.Parameters.
     *
     * @param data
     *         A preview frame.
     * @param width
     *         The width of the image.
     * @param height
     *         The height of the image.
     * @return A ZxPlanarYUVLuminanceSource instance.
     */
    @SuppressWarnings("deprecation")
    public ZxPlanarYUVLuminanceSource buildLuminanceSource (byte[] data,
                                                            int width, int height) {
        Rect rect = getFramingRectInPreview();
        int previewFormat = configManager.getPreviewFormat();
        String previewFormatString = configManager.getPreviewFormatString();
        switch (previewFormat) {
            // This is the standard Android format which all devices are REQUIRED to
            // support.
            // In theory, it's the only one we should ever care about.
            case PixelFormat.YCbCr_420_SP:
                // This format has never been seen in the wild, but is compatible as
                // we only care
                // about the Y channel, so allow it.
            case PixelFormat.YCbCr_422_SP:
                return new ZxPlanarYUVLuminanceSource(data, width, height, rect.left,
                        rect.top, rect.width(), rect.height());
            default:
                // The Samsung Moment incorrectly uses this variant instead of the
                // 'sp' version.
                // Fortunately, it too has all the Y data up front, so we can read
                // it.
                if ("yuv420p".equals(previewFormatString)) {
                    return new ZxPlanarYUVLuminanceSource(data, width, height,
                            rect.left, rect.top, rect.width(), rect.height());
                }
        }
        throw new IllegalArgumentException("Unsupported picture format: "
                + previewFormat + '/' + previewFormatString);
    }

    /**
     * 通过设置Camera打开闪光灯
     */
    public void turnLightOn () {
        if (camera == null) {
            return;
        }
        Parameters parameters = camera.getParameters();
        if (parameters == null) {
            return;
        }

        List<String> flashModes = parameters.getSupportedFlashModes();
        if (flashModes == null) {
            return;
        }
        String flashMode = parameters.getFlashMode();
        Log.i(TAG, "Flash mode: " + flashMode);
        Log.i(TAG, "Flash modes: " + flashModes);
        // 闪光灯关闭状态
        if (!Parameters.FLASH_MODE_TORCH.equals(flashMode)) {
            // Turn on the flash
            if (flashModes.contains(Parameters.FLASH_MODE_TORCH)) {
                parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
                camera.setParameters(parameters);
                camera.startPreview();
            } else {
            }
        }
    }

    /**
     * 通过设置Camera关闭闪光灯
     *
     * @param
     */
    public void turnLightOff () {
        if (camera == null) {
            return;
        }
        Parameters parameters = camera.getParameters();
        if (parameters == null) {
            return;
        }
        List<String> flashModes = parameters.getSupportedFlashModes();
        String flashMode = parameters.getFlashMode();
        // Check if camera flash exists
        if (flashModes == null) {
            return;
        }
        // 闪光灯打开状态
        if (!Parameters.FLASH_MODE_OFF.equals(flashMode)) {
            // Turn off the flash
            if (flashModes.contains(Parameters.FLASH_MODE_OFF)) {
                parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
                camera.setParameters(parameters);
            } else {
                Log.e(TAG, "FLASH_MODE_OFF not supported");
            }
        }
    }
}
